This may sound rather odd, but my smaller Western Hermann tortoise, Belva, wants to bite her sisters head, Hetty, which she's a little bigger. They are both acting normal, active, feeding, bathed and warm. About 30 degrees day and night, am re-doing there home to get temps up to 40 degrees day and night. Has anyone else had or witness this problem before? Belva isn't doing any damage, as Hetty is cleaver enough to duck her head in lol. But I don't want Belva to become a nasty tortoise. Iv already got a nasty musk turtle am losing the battle with and just taken on a handful hamster that needs a lot of TLC :-( any help or advise will be warmly welcomed. Cheers